A workpiece to be thermally treated is often configured so as to turn (autorotate) during a thermal treatment. To turn a workpiece in such a manner, it is necessary to transfer the rotation power to a portion to which the workpiece is to be fixed (workpiece fixing portion). For example, a driving shaft is coupled serially to driven shafts provided to the workpiece fixing portion. Some workpieces are configured so as to turn due to the rotation power transferred from the driving shaft to the driven shaft in the above-described manner.
On the other hand, as a member for conveying a workpiece to be thermally treated, a rotary table is used in some cases (e.g., Patent Literature 1).
A plurality of driven shafts is attached to the table, and workpieces are fixed to the respective driven shafts. The rotary table is turned, the table is stopped at a predetermined position, and the driving shaft is coupled to one driven shaft to turn the workpiece.